Definitely feels like a driveshaft vibration, but could possibly be axles?

If driveshaft, I have no idea which one - and I've heard that these tend to lock "tight" and not "loose" like typical u-joint failures.

The accel vibration is most obvious when pulling out onto a hill and you're pulling through 2nd, towards high end of power band you can feel the shake. If you back off throttle it immediately goes away (which is kinda instinctive at this point, after owning a DII lol).

The decel vibration happens at VERY low speeds, for instance in traffic decelerating from ~15-0mph it feels like I have huge mud terrain tires, just a subtle speed-dependent vibration that slows with the vehicle. Also sometimes noticed in sharp turns in round-abouts at ~15mph.

Based on how far forward the drivetrain actually is (deceptively so) it seems like the rear driveshaft u-joints/carrier would be the culprit.

Next question - if it is indeed the rear, how do people handle the carrier bearing? I assume mine will be shot?

I have complete service records since about 46k miles I believe, no driveshaft or axle work has ever been performed - it now has 112 on it I believe.

***JUST FYI*** I am VERY aware of what differential failure/bearing issues sound like after replacing both in my RRS, as well as what the thumpy-like tire/wheel balance issues sound like. This is neither (and obviously tire vib won't change w/ throttle). I'm also familiar w/ u-joint progressive failure, and how they vibrate when under heavier torque loads, which this seems like. This is NOT the high-frequency humming differential vibration (or the lower freq. groaning the rears can make also) - those also generally don't change too much under full/part/no throttle, more constant. Obviously this is also speed-dependent and NOT RPM-dependent, so it's somewhere past the transmission.

I've had a friend that replaced his front driveshaft, but I've also read about a lot of carrier bearing failures.

 

Well, I don't know that it would cause the issue you're having but at least checking the carrier on the rear shaft is easy enough. The most common failure isn't the bearing at all, but the rubber support. So just grab the driveshaft and see if you can move it near the center joint. You shouldn't be able to get much movement at all. If it's torn, you'll get a lot of movement and it's pretty obvious.

A new center carrier will cost you about $100 and is a bit of work to replace. I did a write up on it on here before. Just replacing the shaft as a unit is easy but expensive - about $700 as i recall.

 

Replacing the shaft as an assembly comes with the carrier bearing right? (I'd think but don't want to assume).

@EstorilM I feel like you're constantly chasing noises!

 

Thanks Zelator - I'm starting to think it's actually the front.

Yeah but that's a Land Rover thing, I pretty much stay on top of everything I can and it's been great for a while lately *knock on wood* but the noise issues are harder to diagnose, especially with the crazy drivelines these things use.

The weirdest thing I've noted since my post was that the slow speed vibration is actually REALLY slow, like 0-5mph in traffic, not 10-15. Sometimes just moving from a stop there's a rumbling type vibration. This is all really subtle of course. It sounds just like if I had HUGE mud terrains on, but obviously I don't so.. seems like a binding u-joint.